Oil burning tobacco curing stove



Nov. 9, 1948. 0. K. KITTRELL OIL BURN ING TOBACCO CURING STOVE r; Sheets-Sheet 1 Filed March 4, 1946 I INVENTOR B 0. KK/TTRELL a; AT ORNEY 0. K. KITTRELL QIL BURNING TOBACCO CURING STOVE Nov. 9, 1948.

2 Sheets-Sheet 2 Filed Match 4, 1946 INVENTOR 0.,K- K/TTRELL -r'r RNEY Patented Nov. 9, 1948 S -PATENT OFFICE OIL BURNING TOBACCO CURING STOVE Ottis Kay Kittrell,"Lumberton, N. C. Application March 4, 1946, Serial No. 651,851-

This invention relates in general to an improved heating device and deals, more particularly, with a'device of this character that is designed for use in tobacco curing barns and the like for the curing of tobacco.

A primary object of the invention is to provide an improved toba'cco curer comprising an oil burning heater having a simplified type of burner unit which operates at maximum efliciency of combustion in-producing a high degree of heat at a relatively low rate of fuel consumption.

A further object of the invention is to provide a tobacco curer of this character which embodies a downdraft arrangement associated with the burner in a manner whereby primary air is evenly supplied to the burner throughout its periphery to insure'a steady uniform how of heat with maximum efficiency of combustion. Another object of the invention is to provide a tobacco curer having such a combined downdraft and burner arrangement in which the downdraft is mounted for adjustment relative to the burner for varying the amount of air supplied thereto so that for any setting of the fuel supply to the burner, the amount of air supplied by the downdraft can be regulated as necessary to insure maximum efliciency of combustion under any" condition.

A further object is for the provision of a tobacco curer of the character described wherein the improved burner comprises an annular fuel chamber carrying a peripheral heat conducting plate which constantly heats the fuel chamber so that the oil therein becomes'hot and vaporized as it is supplied to the burner flame. This provides for complete combustion of the fuel with the result that a clean dry heat is ensured without smoke or the" deposit of carbon or' other waste products of combustion on the burner. In effect, ithas been found that the burning of the hot oil in the manner described serves to keep the burner thoroughly clean at all times so that it requires little attention and there is seldom any occasion for the burner to become clogged or otherwise to stop or impede the flow of fuel thereto. i

Another object of the invention is to provide a tobacco curer or the like embodying all the foregoing features and whichis strong, durable and fool-proof, relatively simple and inexpensive to manufacture, and operates on a minimum of fuel at maximum'efliciency of combustion to provide a relatively high degree of clean, dry heat at comparatively low cost.

With the foregoing objects and advantages in 3 Claims. (Cl. 12693) view as well as other objects and advantages which will be apparent to those skilled in the art as the following description proceeds with reference to the accompanying drawings, the invention comprises the parts and combination thereof hereinafter set forth and claimed with the understanding that the several necessary elements constituting the same may be varied in proportion and arrangement without departing from the nature and scope of the invention as define in the appended claims. In order to make the invention more clearly understood, there are shown in the accompanying drawings, means for carrying the invention into practical effect without limiting the improvements in their useful application to the particular construction and arrangement disclosed, which, for purposes of explanation, have been made the subject of illustration.

In the drawings: 1

Figure 1 is an end elevational view, partly in section, showing the general organization of the improved tobacco curer of the present invention;

Figure 2 is a sectional view taken on line 2-4 of Figure 1;

Figure 3 is a top plan view of the burner unit per se;' and Figure 4 a sectional view of the burner taken on line 4-11 of Figure 3.

While the invention is described and illustrated in connection with its use as a tobacco curer, it is to be understood that the invention is not in any way restricted to such'use inasmuch as it is equally adaptable to various other uses and applications such as, for example, an orchard heater, hothouse heater, or building heater of general utility.

Referring to the drawings. Figures 1 and 2 show a preferred embodiment of the invention comprising a sheet steel base ill supported by legs H or other suitable means and provided with a central opening 52 in which the burner unit, designated generally 50, is positioned.

The body of the heater comprises a hollow generally cylindrical sheet steel drum l5 securedto the base ill by welding I6 or equivalent means. The upper portions [7 of said drum are bent in wardly and so fashioned as to provide at each side of the drum a semicircular opening defined by the arcuate edge 18 and end flanges IS. A cap member 20 having a complementary semicircular cross section is secured adjacent to the upper edges of the drum as by welding 2|, or the like, to define a generally circular flue opening ateach side of the heater body. A flue connecting collar 25 is fitted within each of said flue openings and secured to the drum as by welding 26 or equivalent attaching means. The collars 25 serve to connect the heater to suitable heat conducting fines (not shown) which distribute the heat to selected locations within the tobacco curing barn or other building. Preferably apertured trunnions 21 are attached to the drum as b welding 28 to serve as means for transporting the heater or for mounting the same in certain installations.

At the'front face of the heater body [5, Figure 1, an opening 30 is provided to permit access to the burner for firing purposes. The access opening 30 is covered by a closure panel 3i which is slidably retained between a pair of spaced flanges 52 attached to the drum body in any suitable way and which is provided with a handle 33 for raising or lowering the closure panel as desired. A

peep opening 34 also is provided together witha movable closure plate 35 which is pivotally attached to the drum body so that it may swing'to either side of said opening to permit inspection within the heater body. On either side of the heater body, a series of ports 36, Figure are provided for the entrance of secondary air to the burner.

A downdraft pipe 45 extends through a central opening 5! in the cap 20 of the heater body and is sodesigned that its lower end is in line with and in close proximity to the top of the burner unit 50, Figure 2. Adjacent the upper end of the downdraft pipe, opposed arms 42 are united thereto as by welding, or the like, and each arm includes a threaded opening receiving an adjustable bolt or stop 53 provided with a lock nut 44. The ends of these adjustable bolts 43 engage level abutments 55 welded or otherwise attached to the cap 25 of the drum body so as-to enable a precise and plumb setting of said bolts in any position of adjustment. By turning the bolts43, the downdraft pipe may be raised or lowered as necessary to provide such spacing between the lower end thereof and the burner unit as will pass the amount of air that will give maximum efficiency of combustion for any condition of operation of the heater. In any position of adjustment of the bolts 43, the lock nut 44 on .eachiis tightened against the associated arm 42, thereby locking the bolts to prevent any accidental or unintended rotation thereof which would change their setting and disturb the regulated position of the downdraft pipe.

The burner unit 55 is supported on the base l0 within the drum body l5 substantially in line with the downdraft pipe id. In the embodiment shown in Figures 2, 3 and 4, the burner is a relatively simple and inexpensive structure to manufacture comprising concentrically arranged outer and inner tubular sections 5!, 52, respectively, defining spaced cylindrical walls which are connected along their lower ends by an annular section 53 welded thereto. The space between the cylindrical tube section 55, 52, thus provides an annular fuel chamber in which the fuel is readilyheated and vaporized during the operationof the burner, as presently to be described. While the fuel chamber is shown and described as a simple, inexpensive welded construction, the invention fully comprehends any equivalent arrangement provided by machining or casting a similar part and associated elements of the burner unit.

The inner cylindrical wall 52 of the fuel chamher is provided with an annular groove at its upper end forming a shoulder 54 seatin a burner 4 ring 55 in the space between the cylindrical walls 5|, 52. The burner ring 55 is of such size as to present between it and the outer cylindrical wall 5|, a circular channel 56 defining a constricted fuel passage through which the fuel passes and is ignited in the operation of the burner. The ring 55 is removable for cleaning or replacement purposes and rings of different sizes may be used so asto vary the size of the channel 56 and the passage of thefuel therethrough for any particular installation.

A baffle plate 51 is arranged within the inner cylindrical wall 52 and is secured thereto by weldingr58 orequivalent means. A guide element 59 is welded or otherwise joined to the upper face of the bafiie plate 5'! and is so designed as to be snugly received within the lower end of the downdraft pipe 40, as shown in dotted lines in Figure 1'. -The guide element thus provided serves as a positioning means for the downdraft pipe so that many adjustment thereof by the bolts 43, the downdraft pipe is concentricall arranged with respect to the burner. unit and particularly, the circular fuel passage 56 in order to insure an equal distribution of air throughout the burner. As best seen in Figure 2, the baflie plate 51 is in direct line with the downdraft pipe-and consequently air supplied by the downdraft impinges against the bafile plate and mushrooms outwardly to be equally and evenly distributed around the circular fuel passage 56 as itfiows toward the peripheral space between the end ofthe downdraft, pipe to and the burner unit.

A heat conducting plate 60 in the form of a generally dish-shaped disk extends about the periphery of the outer cylindrical wall 5! of the fuel chamber and is attached thereto as by welding 6! or equivalent securing means. An aperture 62 through the plate has a tube 63 threaded therein for leading ofi any excess overflow of fuel which sometimes occurs in the procedure for igniting the burner.

Preferably the fuel is fed to the burner from the underside thereof and from within the inner cylindrical wall 52 of the fuel-chamber by means of opposed inlets 65 connected by a T-shaped coupling 66 to a fuel supply line, F, provided with a shut-off valve 61, Figure 1, and extending to a suitable fuel reservoir (not shown) I H The burner unit is supported on the base ID of the heater with the fuel chamber defined by the cylindrical walls 5|, '52 extending through the opening l2 therein and the heat conducting plate 60 resting onthe base adjacent said opening. If desired, the burner unit may be fixedly mounted in this position by welding or otherwise securing the plate 6B to said base ii).

In the operation and use of the invention, the valve 61, Figure 1, is opened to allow the fuel to pass through the inlets 65 to fill the annular fuel chamber defined by the spaced, concentric cylindrical walls 5|, 52. Immediately prior to igniting the burner, the fuel is allowed to overflow-the fuel chamber slightly onto the plate 60 where any excess is readily drained down the overflow pipe downdraft pipe and the burner. The convection currents developed cause the flame projecting from the circular channel 56 to assume the form of an outwardly flaring annular band of flame. Through the ports 36 in the heater body, secondary air is supplied to the flame in conjunction with that drawn through the downdraft.

The outwardly flaring band of flame thus provided sets up an intense heat in the circular plate 60, which in turn, heats the outer cylindrical wall 5! of the fuel chamber to which it is connected. This heats the oil within the fuel chamber to such an extent that the fuel is substantially vaporized as it passes through the circular channel 58 to produce the annular band of flame, aforesaid The flame thus provided has a high degree of efliciency of combustion, in any event, and provides an unusually great volume of clean, dry heat without smoking or objectional odors.

When the heater has burned sufiiciently to reach its approximately normal condition of operation, the downdraft pipe is adjusted by the bolts 43 to raise or lower the end thereof adjacent the burner unit as necessary to supply to the flame the amount of air which produces the maximum efiiciency of combustion. The downdraft may be adjusted in this manner at any time to meet varying weather conditions so that in any operation of the heater there is obtained as complete combustion as is possible.

The heating device of the present invention has been found particularly advantageous in that an excellent heat output is assured under all conditions. Moreover, the arrangement for pre-heating and vaporizing the fuel is such that the heater consumes a minimum amount of fuel and otherwise operates at considerably less cost than heretofore known similar devices.

A further advantage resides in the simplicity of construction of the present invention which makes possible the manufacture of a highly practical type of heating device that is relatively inexpensive and sufficiently light in weight to be readily portable for use in different locations and for various applications and uses. To this end, it will be appreciated that in the preferred embodiment which has been described, the complete heating device comprises a highly simplified, unitary, all-welded structure which is strong and durable, and capable of withstanding constant usage and handling over a long period of service.

While the invention has been described in detail with a specific example, such example is intended as an illustration only, since it will be apparent to those skilled in the art that other modifications in the construction, arrangement and general combination of parts thereof may be devised without departing from the spirit and scope of the invention. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, with all changes falling within the scope, meaning and range of equivalency of the claims intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a heating device comprising an oil burner having a central baffle plate and a guide element projecting above said baffle plate, a heater body housing said burner comprising a horizontally disposed hollow drum having flue openings at its ends and an opening in the upper surface thereof for receiving a downdraft pipe, a downdraft pipe extending vertically through said opening in the upper surface of the drum and having its lower end held in operative position by said guide element and overlying the burner but spaced therefrom to permit the outward flow of air from the downdraft pipe to the burner, and means associated with the upper end of the downdraft pipe for adjusting the downdraft pipe axially to vary the spacing of the lower end thereof from said oil burner.

2. In a heating device comprising an oil burner having a central bafile plate and a guide element projecting above said baffle plate, a heater body housing said burner comprising a horizontally disposed hollow drum having flue openings .at its ends and an opening in the upper surface thereof for receiving a downdraft pipe, a downdraft pipe extending vertically through said opening in the upper surface of the drum and having its lower end overlying the burner but spaced therefrom to permit the outward flow of air from the downdraft pipe to the burner, said downdraft pipe having its lower end held in operative position by said guide element and its upper end projecting above the upper surface of the drum, opposed arms on said projecting upper end of the downdraft pipe, and threaded bolts carried by said arms and bearing on the upper surface of the drum, said bolts being adjustable to move the downdraft pipe axially for varying the spacing of the lower end thereof from said oil burner.

3. In a heating device comprising an oil burner having a central baffle plate and a guide plate projecting above said baffle plate, a heater body housing said burner comprising a horizontally disposed hollow drum having flue openings at its ends and an opening in the upper surface thereof for receiving a downdraft pipe and ports in the lower portion of said drum for the passage of secondary air to the burner, a downdraft pipe extending vertically through said opening in the upper surface of the drum and having its lower end overlying the burner but spaced therefrom to permit the outward flow of air from the downdraft pipe to the burner, said guide plate being positioned in the lower end of said downdraft pipe to hold said downdraft pipe in operative relation to the burner with the upper end of said downdraft pipe projecting above the upper surface of the drum, opposed arms on said projecting upper end of the downdraft ipe, and

threaded bolts carried by said arms and bearing on the upper surface of the drum, said bolts being adjustable to move the downdraft pipe axially for varying the spacing of the lower end thereof from said oil burner.

OTIIS KAY KI'I'TRELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 751,968 Wolf Feb. 6, 1904 981,504 Wallace et al Nov. 10, 1911 1,075,948 Shults Oct. 14, 1913 1,559,939 Dahl Nov, 3, 1925 1,675,843 Dahl July 3, 1928 1,756,226 Tiller Apr. 29, 1930 2,265,925 Paiano Dec. 9, 1941 2,271,484 Joyce Jan. 27, 1942 2,294,168 Francis et a1. Aug. 25, 1942 2,444,814 Dowless July 6, 1948 

